Changeable letter sign



May 24, 1938. D BQNETT] 2,118,696

CHANGEABLE LETTER SIGN Filed Sept. 30, 1955 2. Sheets-Sheet 1 ATTORNEYSMay 24, 1938. D, BONE-r11 2,118,696

' CHANGEABLE LETTER SIGN Filed Sept. 30, 1955 2 Sheets-Sheet 2 OQOOGQGGQATTORNEYS'.

Patented May 24, 1938 UNITED STATES PATENT GFFICE 4 Claims.

This invention relates to changeable letter signs, and relates moreparticularly to signs which are equipped with a plurality of memberswhereby to change the legend upon the sign to any desired grouping ofletters.

It is an object of this invention to provide a sign having a pluralityof members carrying a plurality of alphabetical arrangements of letters.

It is another object of this invention to provide a sign which iscapable of being changed within denite limits to make up any combinationof numbers or letters.

It is another object of this invention to provide a sign which can bechanged from one legend to another rapidly and quickly.

It is another object of this invention to provide a sign which can bechanged from one legend to another without the necessity for removingletters and replacing the same.

It is another object of this invention to provide a sign which can bechanged from one legend to another by remote control.

Numerous other objects and advantages will more fully appear during thecourse and progress of the following specification.

Figure 1 is a perspective view of a preferred embodiment of the presentinvention showing the front face thereof.

"0 embodiment of the present invention shown in Figure l showing therear side view.

Figure 3 is a cross-section View of the preferred embodiment shown inFigure 1 about line 3 3 of Figure 1.

Figure 4 is a perspective detail View of the roller member of thepreferred embodiment shown in Figures l, 2, and 3.

Figure 5 is a cross-sectional view of a preferred 40 embodimentsubstantially similar Yto the preferred embodiment shown in Figures 1,2, and 3, showing an interlocking feature.

Figure 6 is a cross-section view of a preferred embodiment of thepresent invention substantially similar to the preferred embodimentshown in Figures l, 2, and 3, but having a reverse winding arrangementfor the letter carrying member.

Figure 'l is a plan View of another preferred embodiment of the presentinvention, this embodiment being equipped with remote control mechanism.

Figure 8 is` a cross-section View of the upper letter carrying track ofthe embodiment shown in Figure 7 about line 8-8 of Figure 7.

Figure 2 is a perspective view of the preferredv Figure 9 is across-sectional view of the preferred embodiment shown in Figure 7 aboutline 9-9 of Figure '7 showing the motor and chain drive assembly indetail.

Figure 10 is a cross-sectional view of the preferred embodiment shown inFigure l about line IIL-II) of Figure 7 showing in detail the rollerdrive mechanism.

Figure 11 is a cross-section View of the roller drive selector mechanismin return position.

Figure 12 is a perspective view of the separator clip which may be usedbetween the rolls in any of the embodiments of the present invention.

One preferred embodiment of the present invention comprises a metalplate I shown in Figure 1. This metal plate is preferably provided withinwardly bent flanges 2, 3, 4, and 5 which extend b-ackwardlyperpendicular to the plane of the face of the plate I so as to form avery shallow box-like member. 'Ihe plate may be provided with any Wordsor letters painted on the face thereof such as the Word PRICE' shown at6, and the word EACH shown at 1. The plate is provided with a pluralityof parallel slots 8, 9, I0, and Il, the slots 8 and 9 being parallel andlying ldirectly one above the other in spaced apart but coextensiverelation to the other. Similarly the slots IIJ and II are parallel andlie directly one above the other in spaced apart coextensiverelationship. 'I'he slots 8 and I0 also lie substantially in the samestraight line. Similarly the slots 9 and II lie substantially in thesame straight line.

Bracket members I2, I3, I4, and I5 are mounted on the back of the plateI, the brackets being provided with holes through which rods I6 and ITmay pass. Obviously the holes in the brackets I2 and I3 are aligned soas to permit the rod I6 to pass therethrough parallel to the surface ofthe plate I and at the same time parallel to the plane of the flange 3.Similarly the holes in the bracket members I4 and I5 are aligned so asto permit the rod Il to pass therethrough and lie substantially in thesame plane as the rod I6 and parallel thereto. The rods I6 and I'I areheld in position by suitable terminal fastening means I8 and I9, and 20and 2| respectively. On the rod I6 and between the brackets I2 and I3are mounted a plurality of roller members 22, 23, and 24 respectively.Similarly on the rod II and between the brackets I4 and I5 are mounted aplurality of roller members 25, 26, and 21 respectively. The rollermembers on the rods I6 and I'I are capable of revolving freelythere-around. The roller members 22, 23, 24, 25, 26, and 21 aresubstantially identical in structure. An enlarged Adetail view of theseroller members is shown in Figure 4. The roller member comprises acentral spindle member 28 and terminal guide members 29 and 3Grespectively. Both of the terminal guide members 29 and 30 are circulardiscs rigidly mounted on the spindle 28 having a diameter substantiallylarger than the diameter of the spindle 28. One of these terminal guidemembers is preferably knurled at its outer periphery to provide asurface to which manual power may be applied in turning the rollermember about the shaft I6.

A long continuous strip of flexible material 32, preferably Cellophane,is wound about the roll 22 and threaded down through the slot I and thenthrough the slot Il, and finally around the roll 25. Any literalcharacters may be inscribed at spaced intervals along the surface ofthis roll. such as numbers or the letters of the alphabet. A similarstrip 33 is wound about the roll 23 and threaded through the slots insimilar fashion and ultimately wound about the roll 26. Similarly astrip 34 is placed in identical position upon the pair of rollers 24 and21 respectively.

It has been found desirable to interpose washers 35 and 36 between theroller members 22 and 23, and 25 and 26 respectively. These washers maybe made of fairly soft rubber or ungreased leather, or even rough metaland fashioned in any way designed to create a certain amount of frictionso that when the roller members are Y turned there will be a smallamount of resistance against turning such as that when the forceinducing the turning is removed the roller member stops immediately anddoes not tend to coast past the desired stopping point. It has also beenfound that spring clip means such as the V-shaped clip shown in Figurel2 may also be inserted between the respective rollers to pro- Vide thisfriction.

It has been found preferable to have each of the Cellophane strips carrya duplicate set of literal characters. Thus if the sign is to be used asa price marker numbers from zero through nine would be printed on eachstrip. In order to set the sign the roll 24 is then turned by applyingtangential force to the knurled guide member thereon so as to rotate itabout the shaft I B and roll up the Cellophane strip onto the rollermember 24 and off of the roller member 21, ultimately bringing thefigure 2 into view. Thus the price of two dollars may be fixed upon thesign as illustrated in the preferred embodiment shown in Figure l. Ifthe item upon which the sign is to be placed is to cost two dollars andforty-five cents for example, the second roll, i. e., roller member 23,is similarly rolled up bringing the figure 4 into View. Likewise thethird roller member, i. e., 22, is rolled up to bring the figure intoview. If the next item upon which the sign is to be used is to cost twodollars and forty-one cents for instance it would only be necessary toapply the rolling movement to the roller member 25, thereby rolling theCellophane strip back up upon the roller member 25 until the figure l isbrought down into View ofi` of the roller 22, whereupon the sign willread 2.41.

If it is desired to have a number of signs which fit together the flangemember 3 may be made of extra width and bent back upon itself to form amember of U-shaped cross-section such as that shown at 3l in Figure 5.The opposite ange 5 is made alittle shorter than normal and is adaptedto t into a similar U-shaped portion on an adjacent sign member 38.

It is also possible to avoid the use of knurled guide members if this bedesirable. The Cellophane strips may be rolled up on the roller membersin the reverse direction as shown in Figure 6, whereupon the manualpressure may be applied to the back of the Cellophane strip directlywithout fear of dirtying the face portion of the Cellophane strip.

Another preferred embodiment of the present invention is shown in Figure'7. This embodiment of the invention is capable of being controlled froma distance and is therefore particularly applicable for use on the frontof moving picture theaters and in the face of the canopies which extendout in front of the movie theater over the street. At the present timein these movie canopies it is customary to have a series of channelsinto which are fitted glass plates carrying the letters. 'I'he wordsmaking up the legends on the sign are composed of a series of glassplates fitted into the channels and slid together. A trough behind theglass plates carries a plurality of light bulbs or some other lightproducing member so that light shines through the glass plates. It alsomakes the letters thereon clearly visible. It is necessary therefore inchanging these signs to crawl out on a cat-walk or mount a ladder andremove the individual letters and replace them or rearrange them in thecourse of changing the legend on the sign. This is extremely bothersome,time consuming, and even dangerous. In addition to this the glassletters frequently crack and are constantly being replaced, all of whichconstitutes an extreme expense in the upkeep of the canopy or sign. Inadapting the present invention to this use it has been found possible toprovide a device capable of remote control whereby the necessity forclimbing around in dangerous places and handling frangible materials isentirely obviated.

The embodiment shown in Figure '7 comprises a sign board 40 carrying aplurality of rows of letters 4| and 42. Each of the rows 4I and 42 mayhave any number of separate letters spaces. The embodiment shown happensto contain nine spaces for letters. The face of the sign board 40 issubstantially similar to the embodiment shown and described inconnection with Figure l and consists of a plurality of slots, a pair ofparallel superposed coextensive slots being arranged for each letterspace. A pair of roller members similar to the roller members shown inconnection with the embodiment shown and described in Figure 1 arearranged adjacent to the slots and on the back of the sign board foreach letter space. Thus as shown in the cross-section view of Figure 8one letter space would consist of the face portion of the sign board 40with a roller member 43 and a roller member 44 mounted on axle members45 and 45 respectively. The axles 45 and 46 respectively are supportedby suitable bracket members 4l and 48 respectively. The roller` member43 is provided with a driving gear 50 at one extremity thereof.Similarly the roller member 44 is provided with a driving gear member 5|at one extremity thereof. Meshing with the roller drive gears 50 and 5lrespectively are the power driven gear members 52 and 53 respectively,which are mounted on the drive shafts 54 and 55 respectively. Obviouslytherefore when it is desired to roll the Cellophane strip upon theroller member 44 this may be accompnsned oy applyilio ing motor power tothe shaft 55 which in turn rotates the gear 53 which meshes with thegear and rolls the roller member 44 about the axle member 46. If it isdesired to roll up the Cellophane strip on the roller member 43 theshaft 54, power driven in similar fashion causes rotation of the member5|! and causes the Cellophane strip to be rolled up thereon and off ofthe roller member 44. It has been found that in signs the circumferenceof the roll of Cellophane on the roller members increases or de creasesdepending on whether the roll is being rolled on 'or off of thatparticular roller memu ber. It has been found necessary to drive the topand bottom roller member of each letter position individually so thatwhen the strip is being rolled up on the upper roller member the drivingmechanism in connection with the loWer member runs free and idle, andconversely when the strip is being rolled up upon the lower member thedriving mechanism associated with the upper member will roll free andidle.V Similarly only one row of letters can be conveniently changed ata time. Therefore it is desirable that all the driving mechanisms forthe Various rolling shafts be powered by one motor. This can beaccomplished by mounting a motor 56 at a convenient point and connectingit to driving sprockets 51, 58, 59, 6U, and 6| through the flexibledrive chain 69 as shown in Figure 9. Thus by reversing the direction inwhich the chain passes over the respective sprockets the direction ofrotation of these sprockets can be or-dered in such a manner that therotary motion transmitted to the roller members will be in the properdirection.

The sprocket 6| is merely an idle sprocket whereby the alignment of thesprocket members 51, 58, 59 and 60 may not be disturbed. Obviously asthe motor revolves all of the sprockets are turned. Therefore it isnecessary to provide clutch members 52, B3, 64, and B5 respectively foreach of the drive shafts shown. These clutch members are solenoidoperated so that by closing the circuit to a given solenoid a givenclutch member may be engaged while all the other clutch members remaindisengaged. Therefore only one selected driving shaft will be in motionthereby causing rotation of only one row of letters.

It is also necessary that each of the yseparate letter places be capableof separate operation. For instance, the particular embodiment shown inFigure '1 shows the letters TUE & WED in the upper row 4|. It might bedesirable to change the rst word in this sign to T I-I E. This wouldnecessitate moving only the roll or strip on which the letter U ismounted rolling it down upon the bottom roll thereof until the letter His brought into view. To this end a selective mechanism must beprovided. A preferred form of this letter selector mechanism is shown incross section at Figure 10. This comprises a clutch member B2 which isoperated by the solenoid 85 through the operating bar 81. This clutchmay be of any conventional design. The idle side of the clutch 58 isconnected to the inner driving shaft 10. An outer driving shaft 1| isslidably mounted over the inner driving shaft 1b so as to slidelongitudinally along the inner drive shaft 19. A long key-way 12 in theinner shaft is adapted to engage a` key on the outer shaft 1! whereby toallow the shaft 1| 'to be rotated with the rotation of the shaft 10 andstill be translatable longitudinally therealong. On the shaft 1| aremounted a plurality of power driven gears 13, 14, and respectively.These gears are adapted to engage the driving gear members 16, 11, and18 which are rigidly mounted on the roller members of the device- Theouter driving shaft 1| is considerably longer than the inner drivingshaft 10 and is closed off at its further extremity 89, therebyproviding a cylindrical space 8| inside its further extremity betweenthe end 8i! of the shaft 1| and the end 82 of the shaft 18. A spring 83is located in this space and normally urges the shaft 1| longitudinallyalong the shaft 1D so that the end '88 of the shaft 1| tends to moveaway from the end 82 of the shaft 18. The forward end 84 of the shaft 1|passes through a suitable bearing and support member 85 which is mountedon the selector member 85. The selector block 86 is provided with achamber 81 into which the end 84 of the shaft 1I ts loosely. Theselector block is also provided with a plurality of stop plates 90, 9|,92 and 93 which pass across the chamber 81 in a plane perpendicular tothe longitudinal axis of the shaft 1|. These stop members may operate ina vertical plane so as to be normally urged by gravity downwardly,thereby to rest on the bottom of the chamber 81 and extend upwardlythere-across or they may be spring urged into such position. Each stopmember is also provided with complementary solenoid members 94, 95, 96,and 91 respectively. 'Ihese solenoid members will retract the stopmembers respectively when the solenoids are appropriately en ergized soas to draw the given stop member upwardly out of the chamber 81. Thedriving gears 13, 14, and 15 which are mounted on the shaft 1| arespaced along the shaft a distance less than the distance between theroller driving gears 16, 11 and 18 respectively. That is to say, thedistance between corresponding points on gears 13 and 14 is less thanthe distance between corresponding points on the gears 16 and 11 by anamount slightly greater than the thickness of the gear 11. Similarly thedistance between the stop member 98 and the stop member 9| is equivalentto slightly greater than the thickness of the gear 11.

The stop plates 99, 9|, 92 and 93 are provided with holes |80, |91, |92,and |03 respectively. The selector carrying member 88 carries a solemnoid |94 at one end. Through the solenoid passes a return setting rod Hwhich is adapted to enter the chamber 81. The rod |65 has a diameterconsiderably smaller than the diameter of the chamber 81' andconsiderably smaller than the diameter of the driving shaft 1|. This rodis normally urged out of the chamber 81 by the spring member |05. Theholes |90, IUI, |92, and |93 in the stop plates 98, 9|, 92, and 93respectively, are large enough to allow the rod |05 to pass therethroughand come into Contact with the end 89 of the drive shaft 1| and yet notallow the end 80 of the drive shaft 1I to pass backwardly into thechamber when the given stop plate is in downwardly extending position.When the solenoid |84 is energized the return setting rod |05 will beforced through the chamber 81 passing through the holes |93, |82, andIGI successively in the respective stop plates and impinging upon theend 88 of the drive shaft 1| urging it backwardly out of the chamber 81against the action of the spring 83. As the rod |05 reaches theextremity of its movement the end 89 of the drive shaft 1| will havepassed outwardly beyond the limits of the stop plates, whereupon thestop plate 90 will drop downwardly behind the upper portion of the end80 of the shaft 1| and against the top of the return setting rod |05, Asthe return setting action of the rod is completed the current to thesolenoid |04 may be interrupted and the spring |85 will retract thereturn setting rod |65 out of the chamber 81'. This will permit the stopplate 5t' to drop completely down across the chamber 8l and rest againstits bottom, completely stopping the shaft 1|. 'I'he completed travel ofthe return setting rod |85 is shown more specifically in Figure 11. Thisreturn setting action is suicient to translate the driving shaft 'lllongitudinally along the inner drive shaft 10 a distance sufficient tomove the gear 13 backwardly toward the clutch member 68 a distancesufficient to bring it out of operative contact with the gear 76. Whenit is desired to move the first roll of letters electrical connection tothe solenoid 94 is completed whereby the stop plate 90 will be retractedout of the chamber 81. The spring 83 will then urge the driving shaftforward into the chamber 8T until it comes to rest against the stopplate 9|. This longitudinal movement of the shaft will bring the gear'I3 transversely along the shaft 'l5 and into engagement with the gear'56. Meanwhile the gear T4 will be just short of engagement with thegear Tl.

The electric circuit to the solenoid 66 may then be closed bringing theclutch 68 into engagement and the circuit in the motor completed wherebythe sprocket 6G will be set in rotation and the shaft turned. This willcause the gear T3 to turn, which in turn operates the gear 'I6 andimparts rolling action to the roller wherebythe Cellophane strip thereonis rolled up upon this roller. After the proper letter has been broughtinto view on this roller it may be desirable to roll up the letters onthe second roller to A. To accomplish this the electrical circuit to thesolenoid S5 is completed, whereupon the stop plate Sil is retracted outof the chamber 81. The spring 83 thereupon urges the shaft 1i forwardinto the chamber 87 until it comes to rest against the stop plate 92.This transverse movement of the shaft 1| will cause the gear 13 to bemoved one space further forward and out of contact on the other side ofthe gear 1E. Meanwhile the gear T4 will be moved forward one positionand brought into operative engagement with the gear T'i', whereupon theclutch circuit and motor circuit may be completed as before and therotation of this roller accomplished. Similarly the third roller may berotated by completing the electric circuit in the solenoid 9.5iwhereupon the stop plate 92 will be retracted, allowing the shaft ll totravel forward until it comes to rest against the stop plate 9S. Thiswill move both gears '|3 and 'I4 forward one more position, whereby thegear |3 will be two positions away from the gear 16, the gear 'i4 willbe one position away from the gear and the gear 'l5 will be movedforward to its third position at which it is in operative engagementwith the gear T8, whereupon the circuits to the clutch and motor mayagain be completed and the rotation of the third roller accomplished. Itwill be seen that in this fashion each roller may be selectivelyrotated.

In case only the first few letters of the legend need changing in aparticular instance it is ol vious that the shaft l will not have movedthe entire distance into the selector chamber. Therefore in resettingthe mechanism the holes |362, iSl, |52, and 53 in the stop plates areprovided so that the return setting rod |l5 may pass therethrough andimpinge upon the end 80 of the shaft 'll forcing it into reset positionwithout the necessity of having to permit it to traverse the entiredistance along the selector chamber. In order to return the apparatus toits original position for subsequent changing of the letters the circuitto the solenoid |04 is closed and the return setting rod |05 broughtinto play, whereupon the shaft 'l'l' is pushed all the way back to itsoriginal starting position where it is held by the stop plate 96 whichwill have dropped into place as previously described. Obviously therollers carrying the Cellophane strips must not rotate too freelyotherwise there would be a tendency to coast past the desired point. Inorder to overcome this diiculty it has been found desirable to provideV-shaped clips such as those shown at |01 in Figure l2. These V- shapedclips may be inserted in between the rollers as shown in Figure l0,whereby to provide suicient friction to prevent any coasting.

Obviously it is desirable to move the Cellophane strips downwardly aswell as upwardly er in other words cause the Cellophane strips to rollup on the bottom rolls as well as to roll up on the top rolls. To thisend a rolling mechanism IME is provided. This rolling mechanism Hi8 isidentical with the rolling mechanism described in connection with Figure10. This mechanism may be provided with a selector similar to theselector described above or it may be possible to provide one selectorfor the entire rotation, top and bottom, the selector being connected tothe top and bottom drive shafts respectively through a yoke member H asshown in Figure 11, provided with coupling means IIE. Thus in changingthe legend on the sign shown in Figure '7 one would press a buttonraising the first stop plate in the selector, allowing the rst drivegear to contact with the rst roller member and then close either theclutch 62 or 63 depending upon whether it was desired to roll the stripupwardly or downwardly, and then close the circuit to the motor toimpart the rotating action to the roll, stopping when the desired lettercomes into view. The next successive letter will be set by closing thecircuit which will raise the second stop plate in the selector mechanismallowing the gears on the second set of rollers to enmesh, repeating theprevious action to impart rotary motion thereto. This process iscontinued successively down the individual letter places rollingupwardly or downwardly as the case may be until the proper letters comeinto view. Where a long rack of letters is employed the spring 83 in theshaft must be rather strong. In order to smooth out the action of such aspring it has been found that air cushioning may be used as shown inFigure l1. This comprises a small bore duct ||2 which opens into thechamber 8l. The duct ||2 is closed at its outer end by a set valve ||3.This valve may be adjusted to allow the air to pass therethrough at anydesired rate. A collar lill is placed about the shaft 'El where itenters the chamber 87 and this collar is provided with a stufling ringwhereby to make a fairly airtight seal. Thus the movement of the shaft7| into the chamber 8l must force the air therein out through the duct||2 and the valve ||3. By regulating the speed of air ow at the valveI3, the cushioning effect can be obtained.

Various multiplicaticns of the various electric circuits involved in theabove embodiment may be applied thereto so that three correspondingrolls of letters on three different sides or faces of a theater canopy,for instance, could be changed at the same time by the action of onemotor so that the signs on all sides of the canopy would read the same.Similarly two different canopies facing on different streets overdifferent entrances to the theater could be so wired in parallelcircuits that legends in comparable positions on both canopies could bechanged by the same action. 1n addition to this a small representativecanopy or miniature device could be constructed in the control room forthe entire mechanism and wired in parallel so that the operator mightobserve what changes are taking place on the signs in front of thetheater without being within vision thereof.

Modifications of this device could be provided so as to serve as scoreboards at baseball and football games. Still other modifications of theabove invention could be made to provide signs in central depotsannouncing the departure of trains by remote control.

It should be noted that the Cellophane strips or similar material aretransparent. The face of the frame member 4i) may be provided with aplurality of apertures or windows lll positioned behind the Cellophanestrips in letterspace position, so that the light normally generated inthe trough behind the signs on the movie canopy or similar structurewill shine through and make the letters clearly visible. If Cellophanestrips are to be used it is thought preferable to use neon tubes in thelight trough rather than ordinary electric bulbs since the neon tubeproduces much less heat and therefore has less deteriorating effect uponthe Cellophane strip. The Cellophane strips have been found to be proofagainst normal weathering action and capable of rendering long serviceunder the conditions to which they are put.

It is also possible in constructing the hand operated changeable lettersign rst described above to substitute toothed wheels on the rollers inplace of the knurled terminal members 29, and provide suitable gearmeans to mesh with these gear' toothed members so that the rotation ofthe rollers might be accomplished by the turning of a small crank. Thiscrank might be detachable. Similarly in a modification of the presentinvention to be adapted to large signs such as those used in moviecano-pies it might be desirable to have a plurality of small wormmembers associated with the roller gear members 43 in place of thedriving gear members 52. These worm members could extend through thefront face of the sign and be operated by a crank or key which might beeither permanently or detaohably mounted thereon. In such a case theoperator of the sign could insert the key or crank and turn each set ofletters into position.

It is thought that the invention and numerous of its attendantadvantages will be understood from the foregoing description and it isobvious that numerous changes may be made in the form, construction andarrangement of the several parts without departing from the spirit orscope of my invention, or sacrificing any of its attendant advantages,the form herein described being a preferred embodiment for the purposeof illustrating my invention.

Having thus described my invention what I claim as new and desire tosecure by Letters Patent is as follows:

1. A changeable sign comprising a face element, a plurality of rollerelements associated with said face element, a plurality of movableelements having literal characters thereon associated with said rollerelements, power driven means associated with the roller elements wherebyto rotate said roller elements, said power driven means comprising asolenoid operated clutch, a primary shaft operably connected to theclutch, a secondary shaft slidably connected to the primary shaft, aplurality of gear means mounted at spaced intervals along the secondaryshaft, and drive gear means on each roller adapted to engage one of thegears on the secondary shaft.

2. A changeable sign comprising a face element, a plurality of rollermeans associated with the face element, a plurality of movable elementsassociated with the roller means and moved thereby, drive means on eachof the roller means, and power driven means for rotating each of therollers selectively comprising a solenoid operated clutch, a primaryshaft operably connected to the clutch, a secondary shaft slidablyconnected to the primary shaft, a plurality of power transmitting meansmounted at spaced intervals along the secondary shaft, said powertransmitting means being so located on the shaft as to engagepredetermined driving means of the roller means,

and means associated with the secondary shaft to move the secondaryshaft longitudinally along the primary shaft, and selectively slidablestop means associated with the secondary shaft to arrest itslongitudinal movement at a predetermined point.

3. A changeable sign including a face element, a plurality of rows ofspaced-apart, axially alined rollers associated with the face element,movable elements having literal characters thereon associated with saidrollers, and V-shaped frictioncreating means disposed in each of thespaces between adjacent axially alined rollers with the arms of theV-shaped means resiliently engaging the sides of adjacent rollerswhereby to restrict the freedom of rotation of the rollers.

4. A changeable sign comprising a face element, a plurality of rollerelements associated with said face element, a plurality of movableelements having literal characters thereon associated with said rollerelements, power driven means associated with the roller elements wherebyto rotate said roller elements, said power driven means comprising asolenoid operated clutch, a primary shaft operably connected to theclutch, a secondary shaft slidably connected to the primary shaft, aplurality of gear means mounted at spaced intervals along the secondaryshaft, and drive gear means on each roller adapted to engage one of thegears on the secondary shaft at only one selected position of thesecondary shaft.

DANTE BONETTI.

